An Affymetrix(r) Gene Chip/R Node System is requested for the central equipment facilities of the Oklahoma Medical Research Foundation (OMRF). The requested instruments will provide investigators with access to the high standard of quality available though the Affymetrix technology for gene expression experiments, large resequencing projects, and human genome scan single nucleotide polymorphisms. In addition, the well-known Affymetrix technology provides the capacity to very rapidly re-sequence up to 30,000 bases of DNA for variants at low cost and at very high reliability. Finally, Affymetrix has developed arrays that permit the determination of alleles at a large number of genomic sites containing single nucleotide polymorphisms (SNPs). The capability now is at approximately 10,000 SNPs per array and is planned to be >100,000 SNPs in 2004, when this instrument would first be available to us. Major investigator user groups at the OMRF and at the University of Oklahoma will use at least 85% of the capacity of this instrument and its accompanying Affymetrix technology for gene expression, for re-sequencing, and for genotyping. This capability will have a substantial impact upon a number of NIH-funded projects now underway, especially by providing technical capacity not now available to them. The two gene array systems now available on this campus support a number of investigators with less expensive and less reliable spotted arrays for gene expression array data collection. Neither of these facilities has comparable genotyping or re-sequencing or SNP genotyping capabilities. Moreover, we suspect that one of the major applications of the requested equipment will be to confirm and extend gene expression results obtained by other less expensive technologies. The equipment package requested includes an array reader, a computer workstation, a fluidics station, and a hybridization station, multiple training sessions, easy access to technical assistance, and maintenance for the first year. The expense for support for instrument use and the maintenance contracts in future years will be borne by the OMRF.